#include <iostream>
using namespace std;

class Stack
{
public:

	Stack(int capacity)
		:_top(0)
		, _capacity(capacity)
	{
		_a = (int*)malloc(sizeof(int) * capacity);
		if (_a == nullptr)
		{
			perror("malloc fail");
			exit(-1);
		}
	}

private:
	int* _a;
	int _capacity = 4;
	int _top = 0;
};

class A
{
public:
	A(int a) :_a(a)
	{
		cout << "A(int a):_a(a)";

	}

	A(const A& aa)
	{
		_a = aa._a;
		cout << "A(const A& aa)" << endl;
	}
private:
	int _a;
};

int main()
{
	//Stack s1(4);
	A aa = 2;

}